[Lldb-commits] [lldb] b109912 - [lldb] [gdb-remote] Always send PID when detaching w/ multiprocess

[Michał Górny via lldb-commits]

Author: Michał Górny
Date: 2021-09-20T13:29:07+02:00
New Revision: b1099120ff963d0a0f1de12e3315b1ee4e4ed7e7

URL: https://github.com/llvm/llvm-project/commit/b1099120ff963d0a0f1de12e3315b1ee4e4ed7e7
DIFF: https://github.com/llvm/llvm-project/commit/b1099120ff963d0a0f1de12e3315b1ee4e4ed7e7.diff

LOG: [lldb] [gdb-remote] Always send PID when detaching w/ multiprocess

Always send PID in the detach packet when multiprocess extensions are
enabled.  This is required by qemu's GDB server, as plain 'D' packet
results in an error and the emulated system is not resumed.

Differential Revision: https://reviews.llvm.org/D110033

Added: 
    

Modified: 
    lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
    lldb/test/API/functionalities/gdb_remote_client/TestGDBRemoteClient.py

Removed: 
    


################################################################################
diff  --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
index 829fb328a130..d949cfe7a64e 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
@@ -1543,14 +1543,16 @@ Status GDBRemoteCommunicationClient::Detach(bool keep_stopped,
     }
   }
 
-  if (pid != LLDB_INVALID_PROCESS_ID) {
-    if (!m_supports_multiprocess) {
-      error.SetErrorString(
-          "Multiprocess extension not supported by the server.");
-      return error;
-    }
+  if (m_supports_multiprocess) {
+    // Some servers (e.g. qemu) require specifying the PID even if only a single
+    // process is running.
+    if (pid == LLDB_INVALID_PROCESS_ID)
+      pid = GetCurrentProcessID();
     packet.PutChar(';');
     packet.PutHex64(pid);
+  } else if (pid != LLDB_INVALID_PROCESS_ID) {
+    error.SetErrorString("Multiprocess extension not supported by the server.");
+    return error;
   }
 
   StringExtractorGDBRemote response;

diff  --git a/lldb/test/API/functionalities/gdb_remote_client/TestGDBRemoteClient.py b/lldb/test/API/functionalities/gdb_remote_client/TestGDBRemoteClient.py
index a58de7f19ec6..03ef4a73af50 100644
--- a/lldb/test/API/functionalities/gdb_remote_client/TestGDBRemoteClient.py
+++ b/lldb/test/API/functionalities/gdb_remote_client/TestGDBRemoteClient.py
@@ -354,3 +354,46 @@ def QEnvironment(self, packet):
           "QEnvironmentHexEncoded:4e45454453454e43343d6623726f62",
           "QEnvironmentHexEncoded:455155414c533d666f6f3d626172",
         ])
+
+    def test_detach_no_multiprocess(self):
+        class MyResponder(MockGDBServerResponder):
+            def __init__(self):
+                super().__init__()
+                self.detached = None
+
+            def qfThreadInfo(self):
+                return "10200"
+
+            def D(self, packet):
+                self.detached = packet
+                return "OK"
+
+        self.server.responder = MyResponder()
+        target = self.dbg.CreateTarget('')
+        process = self.connect(target)
+        process.Detach()
+        self.assertEqual(self.server.responder.detached, "D")
+
+    def test_detach_pid(self):
+        class MyResponder(MockGDBServerResponder):
+            def __init__(self, test_case):
+                super().__init__()
+                self.test_case = test_case
+                self.detached = None
+
+            def qSupported(self, client_supported):
+                self.test_case.assertIn("multiprocess+", client_supported)
+                return "multiprocess+;" + super().qSupported(client_supported)
+
+            def qfThreadInfo(self):
+                return "mp400.10200"
+
+            def D(self, packet):
+                self.detached = packet
+                return "OK"
+
+        self.server.responder = MyResponder(self)
+        target = self.dbg.CreateTarget('')
+        process = self.connect(target)
+        process.Detach()
+        self.assertRegex(self.server.responder.detached, r"D;0*400")